It is often desirable during surgery, to collect blood from the patient and subsequently return the collected blood to the same patient. Returning the patient's own blood eliminates or reduces the need for supplying the patient with blood from another person and therefore reduces the danger of transmitting a disease to the patient.
After lung surgery, for example, suction is generally applied to the pleural cavity of the patient by means of a catheter connected to a thoracic or chest drainage unit. Blood and gas flow into the drainage unit during the healing process. The collected blood and drainage unit are eventually discarded. If the patient requires blood, stored blood generally from another person must be infused into the patient.
More recently, auxiliary autotransfusion blood collection containers have been employed with chest drainage units which permit reinfusion of the collected blood.
In one case, a blood collection bottle which is non-collapsible is connected to a chest drainage unit such that suction is applied through the bottle to the patient. After the bottle is filled with drainage blood it is used to reinfuse the patient. There are, however, certain problems or disadvantages associated with rigid or non-collapsible autotransfusion bottles. For example, during reinfusion the rigid bottle must be vented to atmosphere to allow the collected blood to flow from it to the patient. Thus, air is in contact with the blood and may affect the blood characteristics. Special care must be taken to avoid infusion of air into the patient during reinfusion. Also, an air filter at the vent must be used to avoid possible air-borne contaminants.
In another arrangement, an auxiliary blood collection device includes a pliable bag having an outer sleeve. The bag is held in an open or expanded condition by a stent or holder having rigid wire arms extending between the bag and sleeve to maintain the bag open for receiving drainage blood against the suction forces during operation of the chest drainage unit. After the bag is filled, it can be removed from the holder and employed to reinfuse the patient with the collected blood. One problem associated with this arrangement is that the volume of the pliable bag generally varies to a significant extent with different suction forces because the walls of the bag tend to move inwardly, especially at locations between the holder arms. Thus, the indicated amount of blood collected may be inaccurate where the operating suction force or negative pressure in the bag differs from a predetermined value.